The present invention relates to a fiber material having a function for sustainedly discharging a skin care component with a resistance to washing from the fiber, as well as being superior in feeling and moisture absorbing and releasing properties, and a method for manufacturing the same. The fiber material of the present invention can be suitably utilized in a clothing field such as underwear and shirts.
xcex1-Tocopherol is a natural antioxidant agent, and widely used in cosmetics and foods for health for the purposes of skin care and health maintaining. Since before, this xcex1-tocopherol has been tried to be applied to fiber products for a purpose of skin care or antioxidant function. However, since xcex1-tocopherol is oxidized and loses its antioxidant function in a short time even if it is simply treated on a fiber, it has become an important subject to stabilize xcex1-tocopherol.
For example, JP-A-10-331070 discloses an antioxidant fiber material, wherein an antioxidant agent is stabilized by forming a complex with a protein followed by treating fiber products with this complex. However, although said antioxidant fiber material is superior for the use in a field of a food packaging material, it has an improved point in feeling for an application to a clothing field. The disclosure has no description on an application to a clothing field. In addition, although the antioxidant agent is stabilized and has a resistance to washing, it does not have a property to be sustainedly discharged by an action of a fat and oil component such as sebum, even if the antioxidant fiber material is used in a clothing field.
JP-A-11-172522 also discloses a method for adding an antioxidant agent in a regenerated cellulose fiber, wherein an antioxidant agent is stabilized by forming a complex between the antioxidant agent and a protein, then said complex is added and mixed in a cellulose viscose solution to be spun. In this method in which a complex is formed between an antioxidant agent and a stabilizer such as protein then blended in a cellulose viscose solution to be used for manufacturing a fiber, an antioxidant agent is stabilized and has a superior resistance to washing, but the antioxidant agent hardly expresses an effect in wearing when applied to clothing because it takes a long time for said complex to migrate to a fiber surface due to being mixed inside of a fiber, and also the antioxidant agent does not have a property to be sustainedly discharged by an action of a fat and oil component such as sebum.
JP-A-10-131042 discloses a fiber treatment agent in which an antioxidant agent such as tocopherol is dispersed in a water phase. The disclosure describes that this fiber treatment agent added on clothing as a finishing agent can suppress a smell of sweat in wearing soon after washing and the deodorizing effect last long, but it does not give any consideration to a deterioration of the antioxidant agent when the clothing is left for a long time after washing.
Further, JP-A-2000-110067 discloses that a fiber stuck with xcex1 type tocopherol in a ratio of 0.01 to 0.5 parts by weight of xcex1 type tocopherol per 100 parts by weight of fiber has effects to quicken circulation of the blood and suppress a rash, but said fiber is mainly used for throwaway fiber products because it has no resistance to washing.
The present invention was completed by paying an attention to xcex1-tocopherol acetate having a superior stability instead of unstable xcex1-tocopherol, in order to solve the above described problems in the conventional arts. Objects of the present invention is to give a resistance to washing by sticking xcex1-tocopherol acetate on a fiber material without losing the feeling and the moisture absorbing and releasing properties possessed by a fiber itself, and to provide a functionalized fiber material having a skin care effect enabling to sustainedly discharge xcex1-tocopherol acetate by an action of a fat and oil component such as sebum present on a skin surface of the human body, and a method for manufacturing the functionalized fiber material to obtain it.
The present invention provides a functionalized fiber material in which xcex1-tocopherol acetate is stuck on a fiber material, wherein xcex1-tocopherol acetate is stuck in an amount of 0.3 mg to 45.0 mg per 1 g of fiber material. The present invention also provides a method for treating a fiber material with an emulsion of xcex1-tocopherol acetate having a concentration of 0.5 to 100.0 g/l of xcex1-tocopherol acetate which is emulsified using a surfactant, and a manufacturing method wherein the surfactant used for the emulsification is an anionic surfactant alone or a mixture of an anionic surfactant and a nonionic surfactant.
A fiber material used in the present invention includes a natural fiber such as cotton, wool, silk, etc., a regenerated fiber such as rayon, polynosic, cellulose acetate, etc., and a synthetic fiber such as polyester, nylon, acryl, etc., and may be a mixed fibers made of one or more kinds thereof. In addition, in the case of a regenerated fiber or a synthetic fiber, these fiber materials may contain a substance to express other functional properties, which is not specially limited so long as the substance does not impede the sustained discharge function of xcex1-tocopherol acetate. Form of a fiber material may be any of raw fiber, spun yarn, knitted or woven fabric, as well as a sewed fiber product. And in the case when a fiber material is a raw fiber, spun yarn or knitted or woven fabric, it is used for clothing.
xcex1-Tocopherol acetate used in the present invention may be an extract from natural products (d-xcex1-tocopherol acetate) or a synthetic compound (dl-xcex1-tocopherol acetate), and is not specially limited. Further, in the case of d-xcex1-tocopherol acetate which is an extract from natural products, it may be mixed with a homologue such as xcex2-tocopherol and xcex3-tocopherol or tocotrienol.
A surfactant to emulsify the above described xcex1-tocopherol acetate in water is preferably an anionic surfactant alone or a mixture of an anionic surfactant and a nonionic surfactant. The anionic surfactant used here is not specially limited, and includes, for example, various kinds of fatty acid soaps, sodium lauryl sulfate, sodium higher alcohol sulfate, sodium dodecylbenzenesulfonate, sodium dialkylphosphosuccinate, calcium alkylphosphate, sodium polyoxyethylenealkylether sulfate, and the like. And nonionic surfactant to be used in combination with an anionic surfactant includes, for example, polyoxyethylene derivatives, sorbitan monoalkylate, sorbitan dialkylate, sorbitan trialkylate, and the like. A surfactant is not specially limited, but may be suitably selected from these surfactants. Further, a mixing ratio of an anionic surfactant and a nonionic surfactant is not specially limited, but is preferably nearly equal.
A method for manufacturing a functionalized fiber material of the present invention is as follows. Firstly, an emulsion containing xcex1-tocopherol acetate is prepared by emulsifying xcex1-tocopherol acetate in water with a surfactant by mixing and stirring. A fiber material is dipped in the emulsion, squeezed at a squeeze ratio of 60 to 120%, then dried and treated at 80 to 200xc2x0 C. for 1 to 30 minutes.
A concentration of xcex1-tocopherol acetate in the emulsion when a fiber material is treated is preferably in a range of 0.5 to 100.0 g/l. A concentration out of this range is not preferable because xcex1-tocopherol acetate hardly remains after washing at a concentration lower than 0.5 g/l, and an emulsification becomes difficult at a concentration over 100.0 g/l.
A concentration of a surfactant in the emulsion is not specially limited so long as the concentration is within a range enabling to emulsify, but a preferable concentration is as low as possible within a range enabling to emulsify, because too high concentration of a surfactant to an amount of xcex1-tocopherol acetate used lowers a resistance to washing. A method for stirring is not specially limited, and may be stirring using, for example, a homogenizer.
Further, in emulsifying, xcex1-tocopherol acetate can be emulsified alone, but more preferably an organic solvent can be used in combination in order to adjust a concentration and a viscosity of the emulsion. Any organic solvent may be used here so long as the solvent can dissolve xcex1-tocopherol acetate. For example, oleic acid, squalane and derivatives thereof, hexane, dimethylether, ethyl acetate and dodecanol and the like are preferably used, alone or in mixture of two or more of them.
xcex1-Tocopherol acetate being stuck on a functionalized fiber material obtained by the method of the present invention has a superior resistance to washing, showing that xcex1-tocopherol acetate of not less than 50% remains after 10 times of repeated washings by an usual method. This is presumed to be caused by a very low hydrophilic property of xcex1-tocopherol acetate emulsion, as well as an addition by impregnating into an inside of a fiber material.
According to the present invention, xcex1-tocopherol acetate stuck on a functionalized fiber material is presumed to be gradually dissolved in a fat and oil component such as sebum remaining on a skin surface of the human body in wearing, sustainedly discharged on a skin surface, and express a skin care effect by being incorporated inside of a skin. Furthermore, a functionalized fiber material manufactured according to the present invention gives little effect on feeling and moisture absorbing and releasing properties essentially possessed by a fiber material.